Not for ‘Humans’! NASA finds another ‘solar system’ like ours
Washington, December 15: Last year NASA made a surprising announcement of discovering a solar system which is 40 light years away consisting of seven Earth-sized planets orbiting a star called TRAPPIST-1, on Thursday NASA again announced of another discovery from Kepler telescope where it captured an eighth planet in a distant star system called Kepler 90 - the first time a faraway star has been found to have the same number of planets orbiting it as our own sun.
The Kepler-90 planets have a similar configuration to our solar system, with small planets orbiting close to their star and the larger planets found farther away.
The new planet, estimated to be about 30 percent larger than Earth, is 'not a place you'd like to visit,' said Andrew Vanderburg, astronomer and NASA Sagan Postdoctoral Fellow at The University of Texas, Austin. "It is probably rocky, and doesn't have a thick atmosphere". And, temperatures at the surface are "scorching".
According to Vanderburg, the average surface temperature is likely around 427 degrees Celsius. The Kepler planet-hunting satellite has been searching the stars for distant worlds using Google's AI system, which used machine learning to "find" planets in the Kepler data with up to 96 percent accuracy.
"After showing our model 15,000 signals, the neural network learned how to distinguish patterns from actual planets from patterns that are caused by other objects," said Christopher Shallue, the senior software engineer at Google AI in Mountain View, California.
"We used our model to identify two new planets from a set of 670 stars," Shallue explained. "One of these two planets is called Kepler 80g. The planet we are focusing on today is called Kepler 90i, which is the eighth planet in its star system. This is a really exciting discovery, and we consider it to be a success, in the use of neural networks in the search for distant worlds, the expert explained.
The star system sits roughly 2545 light-years from Earth in the constellation Draco, and of the new planets found, Kepler 90i is the "smallest of the bunch".
The new planet orbits its star once every 14.4 days. But, all of the planets in this system 'tightly' orbit their star, which is thought to be cooler than our own sun, meaning their orbital periods are relatively short. Before the latest AI-guided results, "Kepler 90 was tied with Trappist-1, with 7 planets each," says Jessie Dotson, Kepler project scientist at NASA's Ames Research Center in California's Silicon Valley.
"But now, it ties with our own system with the most known number of planets" around a star. The Kepler 90 system was first discovered back in 2013. It was the first seven-planet system identified with the telescope. But, the eighth planet remained undetected for years – until Google's AI picked up on its "weak" signal.
While the discovery is exciting, this particular system isn't the most promising for the possibility of hosting life. All of its planets are packed close to the star. All eight planets of Kepler 90 sit closer to their host star than Earth is to the sun; in our own solar system, on the other hand, only Mercury and Venus have such tight orbits. Kepler 90i is about as hot as Mercury, while the outermost planet in the system, Kepler 90h, is a gas giant roughly the size of Jupiter. The other newly discovered planet, Kepler-80g, is now known to be the sixth in the system.